Protective effects of melatonin as an eye drops against selenite-induced cataract in rat pups

The aim of the present study is to investigate the possible role of melatonin, when administered as an eye drops, in the selenite-induced cataractogenesis in rat pups. Sixty Wistar albino rats [13 days old] were allocated into three groups [20 animals each]. group A injected subcutaneously with normal saline and received no other treatment served as control; group B injected with [40 micro mol/g body weight] sodium selenite subcutaneously, and treated with 1 drop of melatonin eye drops, specially formulated for this purpose, twice daily for 30 days; group C injected with sodium selenite as in group B, but treated with single drop of normal saline, twice daily for 30 days. The stage of cataract development was examined with slit-lamp photographs. Alter 30 days the pups were sacrificed and their eyeballs enucleated for histological examination. The results demonstrated that melatonin eye drops decreased the nuclear cataract formation after 15 and 21 days of treatment, compared to saline treated group. Histological evaluations of enucleated lenses revealed that treatment with melatonin drops clearly indicated recovery of the lenticular tissues and retained their ordinary shape. These findings demonstrate that melatonin when administered as an eye drops protects the lens of rat pups against selenite-induced cataract

Comparação da eficiência dos caldos de enriquecimento seletivo no isolamento de Salmonella Dublin / Comparison of the efficiency of selective enrichment broths for Salmonella Dublin isolation

The aim of this study was to compare three different selective enrichment broths: Rappaport-Vassiliadis (RV), selenite cystine (SC) and Muller-Kauffmann tetrathionate (MKT) for Salmonella Dublin isolation from faecal samples of calf experimentally infected. The bacteriological procedure involved pre-enrichment stages in Hajna-GN broth (only for the samples inoculated in RV broth), selective enrichment, culture in modified brilliant green agar (BGA), presumptive biochemistry tests (using triple-sugar-iron agar and lysine-agar) and slide agglutination test with poli-O and poli-H Salmonella antiserum. The effects of enrichment temperatures using RV broth were also evaluated (37ºC and 42ºC). SC broth was significantly more efficient in the isolation of Salmonella Dublin (P<0,05), whereas RV broth incubated at 42ºC had a lower efficiency in the microbiological isolation.